The present invention relates to a high-temperature battery, in particular for supplying power to vehicles with electric drives, having a thermally insulating housing in order to avoid thermal losses and a cooling system in order to limit the operating temperature during charging of the battery and during the power.
In view of their comparatively high energy density, high-temperature batteries are particularly advantageous for electric vehicles. These high-temperature batteries must be thermally well insulated in order to avoid thermal losses. On the other hand, batteries of this kind require a cooling system in order to avoid excessive heating of the battery during the power drain or during the charging of the battery.
In principle, the dissipated heat of the cooling system can be utilized to heat the passenger compartment of a vehicle. However, the quantities of dissipated heat are relatively small in comparison with the required heating power.
Therefore, there is provision according to German Patent Document DE 41 41 811 C1 to preheat the vehicle when charging the battery, that is to say when the vehicle is connected to an external electric mains and, during driving mode, essentially only to maintain the temperature to which the vehicle has been heated and which was already achieved by the preheating. The dissipated heat of the high temperature is usually sufficient to maintain the temperature to which the vehicle has been heated.
Here, the general idea of using the dissipated heat of the cooling system of the battery as a parked vehicle heater when the battery is being recharged so that the passenger compartment of the vehicle can be heated during the charging phase is realized.
Under climatically very unfavorable conditions, additional electric heating of the vehicle can be carried out via the electric mains from which the battery is recharged.
Furthermore, the thermal energy of the high temperature battery can also be exploited by permitting, during the charging of the battery, a temperature rise up to the maximum acceptable operating temperature. In this way, it can then be made possible for an appropriately increased quantity of heat to be exploited for heating the vehicle while driving, by means of the cooling system-of the battery.
With respect to the cooling system in the case of air cooling a battery it is known from German Patent Document DE-A 26 38 862 to provide cooling air channels enclosed within the battery and in particular to avoid a connection to the charging openings of the battery cells so that the gases released by the battery cells cannot get into the passenger compartment. This gives the cooling system an overall constructionally complex structure.
An object of the invention is to simplify constructionally the cooling of a high-temperature battery with the highest possible degree of protection against gases and vapors or the like escaping.
This and other objects are achieved according to the invention in that, in order to remove heat from the battery, a cooling element through which air flows is arranged inside the thermally insulating battery housing, is hermetically sealed and only penetrates the thermally insulating wall of the battery housing with air inlet and air outlet connecting elements arranged on it. Here, according to a certain preferred embodiments of the invention, there is provision for the cooling element to be constructed essentially in the form of a plate-shaped hollow element with the plate in a horizontal plane.
The cooling element can then be prefabricated as a constructional unit and be mounted as a complete unit when the battery housing is installed so that there is a significant overall reduction in manufacturing complexity. At the same time, a high degree of protection against gases and vapors and the like escaping is provided.
Construction of the cooling element as a plate shaped hollow body provides the particular advantage that on the one hand, if necessary, relatively large quantities of heat can be absorbed and conducted away by virtue of a structure with a large surface. On the other hand, only a virtually negligible convection flow occurs within the hollow element so that, without special measures, an undesired heat loss to the outside can be avoided, for example if it is not necessary to cool the battery. Essentially, appreciable quantities of heat can only be removed from the battery if the cooling element is positively ventilated by means of a blower or the like.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.